Communication system for inductive power transfer system

摘要

Methods and apparatus for communication with inductive power transfer (IPT) pick-up devices are disclosed. The IPT system (1) has a primary conductive path (2) and a number of pick-ups (3) that receive energy from current in the primary path to supply a load. An instruction is transmitted over the primary path to a pick-up, the pick-up provides a response by supplying power to the load to induce a predetermined variation in the current in the primary conductive path, and the response is determined by detecting the variation in current.